Effects of cognitive stress (time pressure, concurrent tasks, cognitive conflict) and emotional stress (anxiety) on working memory were examined. Time pressure in discrimination tasks accelerated the stimulus evaluation process measured by P300 latency and response preparation process estimated by LRP latency, depending on task requirements. Cognitive conflict in a flanker task affected the response times. The response times in congruent trials became longer as the amount of conflict in the preceding incongruent trial increased. This suggested the cognitive control mechanism of response inhibition, a part of which was supported by central executive function. The working memory in sentence comprehension was affected by time pressure, concurrent tasks, and state anxiety. Time pressure interfered with the construction of text-based model of the legend. The random generation as a secondary task delayed the sentence verification time and attenuated the semantic priming effect reflected in N400 amplitude, suggesting the disturbance of context formation in a central executive. The secondary tasks affecting the phonological loop did not raise these disturbing effects. The relation between capacity of working memory and reading strategy was dependent on emotional states. Compensatory strategies such as a reading regression were more frequent for low-span than for high-span readers. However, anxiety evoked by negative feedback of the reading performance increase the use of this compensatory strategy of high-span readers, probably in order to reduce the load in working memory coping with a consumption of working memory resource caused by anxiety. The anxiety also affected self referent processing. In an incidental learning task, participants with less anxiety showed the self-reference effect. However, increased anxiety diminished this memory phenomenon. Besides, cognitive and affective factors in social communication and stress coping behavior were investigated.